1. Field of the Invention
The present invention relates to paper-making machines, and, more particularly, to trim squirts for use in paper-making machines.
2. Description of the Related Art
Paper-making machines typically include a head box which discharges a fiber suspension stream with a known cross-sectional profile onto a wire in a fourdrinier section. The wire carries the fiber web to a forming section, where the fiber web is transferred from the wire to the forming section. The lateral side edges of the fiber web which is carried by the wire typically are of poor quality. Accordingly, it is common to discharge the fiber suspension from the head box onto the wire with a width which is wider than the working width of the forming section. The fiber web is trimmed in the fourdrinier section using a pair of trim squirts which are placed along respective lateral side edges of the fiber web. Each trim squirt discharges a water stream at a relatively high velocity to cut the lateral side edges from the fiber web.
It is important that a trim squirt provide a continuous cut of the fiber web as the fiber web travels past the trim squirt toward the forming section. If the fiber web is not continuously cut, the fiber web will normally tear when it is transported to the narrower width forming section. An intermittent pause in cutting can be caused by a pressure fluctuation or an air bubble in the pressurized water which is supplied to the nozzle cutter of the trim squirt. Conventional trim squirts typically provide a pressurized fluid directly from a pump or the like to the nozzle cutter of the trim squirt. The flow velocity of the water is therefore affected by pressure fluctuations associated with rotational speed fluctuations of the pump. It is therefore possible that the fiber web may intermittently not be cut, thereby possibly resulting in tearing of the fiber web. Moreover, no provisions are made to remove air bubbles from the pressurized water which can likewise result in the web intermittently not being cut. Such air bubbles can occur from agitation or turbulence of the pressurized water.
What is needed in the art is a trim squirt which operates at a more constant pressure and without air bubbles to thereby ensure that the fiber web is continuously cut.